Small-Angle Neutron Scattering from Hydrated Cement Pastes

1994 ◽  
Vol 376 ◽  
Author(s):  
L.P. Aldridge ◽  
W.K. Bertram ◽  
T.M. Sabine ◽  
J Bukowski ◽  
J.F. Young ◽  
...  
Keyword(s):  
Data Analysis ◽  
Neutron Scattering ◽  
Cement Paste ◽  
Small Angle ◽  
Calcium Silicate ◽  
Small Angle Neutron Scattering ◽  
Calcium Silicate Hydrate ◽  
Hydrated Cement ◽  
Cement Pastes ◽  
Hydrated Cement Paste

ABSTRACTSmall angle neutron scattering (SANS) has been used to examine hydrated cement pastes with water-to-cement ratios between 0.25 and 0.8 and cured for 28 days. Various methods of data analysis are applied to the pastes.Fitting the entire SANS spectra of the hydrated cement paste has suggested that there are two scattering entities in the paste. There is some evidence to suggest that one scattering entity is globules of calcium silicate hydrate formed in the hydrated paste.

Microstructure Determination of Calcium-Silicate-Hydrate Globules by Small-Angle Neutron Scattering

2012 ◽  
Vol 116 (8) ◽  
pp. 5055-5061 ◽  
Author(s):  
Wei-Shan Chiang ◽  
Emiliano Fratini ◽  
Piero Baglioni ◽  
Dazhi Liu ◽  
Sow-Hsin Chen
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Calcium Silicate ◽  
Small Angle Neutron Scattering ◽  
Calcium Silicate Hydrate

scholarly journals The Small-Angle Neutron Scattering Data Analysis of the Phospholipid Transport Nanosystem Structure

2018 ◽  
Vol 1023 ◽  
pp. 012017 ◽  
Author(s):  
E.V. Zemlyanaya ◽  
M.A. Kiselev ◽  
E.I. Zhabitskaya ◽  
V.L. Aksenov ◽  
O.M. Ipatova ◽  
...  
Keyword(s):  
Data Analysis ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Scattering Data ◽  
Phospholipid Transport

Small-angle neutron scattering as a probe to decide the maximum limit of chemical waste immobilization in a cement matrix

2014 ◽  
Vol 47 (1) ◽  
pp. 421-429 ◽  
Author(s):  
A. Das ◽  
S. Mazumder ◽  
D. Sen ◽  
V. Yalmali ◽  
J. G. Shah ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Scattering Length ◽  
Cement Matrix ◽  
Hydrated Cement ◽  
Composite Cement ◽  
Waste Loading ◽  
Maximum Limit

Immobilization of low- and intermediate-level radioactive waste in a cement matrix is an important process in any nuclear industry. In this regard, setting the maximum limit of waste loading in cement is a crucial issue and one that significantly depends on the mesoscopic density fluctuations of the composite cement matrix. Small-angle neutron scattering (SANS), a technique that maps coherent neutron scattering length density fluctuation, is efficient in monitoring the degree of homogeneity of a condensed matrix. It is prudent, then, to use SANS to probe the degree of homogenization in a composite cement matrix upon immobilization of low-level non-heat-generating radioactive waste. In the present work, the effects of loading of simulated cerium waste on the mesoscopic structure of hydrated cement have been investigated by SANS complemented by scanning electron microscopy and mercury intrusion porosimetry. Utilizing the multiple-scattering phenomenon, the scattering mean free path has been estimated, which has a direct relevance to the degree of homogenization of the waste-loaded cement matrix as far as the neutron scattering length density is concerned. It has been revealed that the structure of hydrated cement becomes less consolidated because the mass fractal dimension decreases with an increase in waste loading. Scattering data unveil the existence of pores at two widely separated length scales. The size of the larger pores increases with loading beyond a certain concentration. However, no significant modification has been observed for the pores on the smaller length scale.

Microstructural Investigation of Carbonation of Calcium Silicate Hydrate in Hydrated Cement Paste

2011 ◽  
Vol 261-263 ◽  
pp. 601-605 ◽  
Author(s):  
Wei Chen ◽  
Wen Bing Xu ◽  
Yuan Li
Keyword(s):  
Cement Paste ◽  
Calcium Silicate ◽  
Microstructural Characterization ◽  
Hydration Product ◽  
Hydrated Cement ◽  
Polymerization Degree ◽  
Reinforced Concrete Structure ◽  
Microstructural Investigation ◽  
Carbonation Reaction ◽  
Hydrated Cement Paste

Carbonation is one of the most common degradation reactions of concrete which greatly shortens the service life of steel-reinforced concrete structure. The carbonation of synthetic calcium silicate hydration derived from hydrated cement paste is investigated with microstructural characterization method including scanning electron microscopy, X-ray diffraction analysis, coupled TG-DSC analysis and Fourier transform infrared spectroscopy. The changes in the morphology, mineral composition and polymerization degree of the calcium silicate gel before and after the carbonation are investigated. The major finding of the research includes that the C-S-H collapses during the carbonation reaction, which actually densifies the microstructure. The major hydration product is calcite. The carbonation resistance of C-S-H is enhanced with increasing C/S ratio. The polymerization degree of C-S-H is increased by the carbonation reaction.

An investigation on the nature of porosity in hardened cement pastes using small angle neutron scattering

1983 ◽  
Vol 18 (2) ◽  
pp. 430-438 ◽  
Author(s):  
D. Pearson ◽  
A. Allen ◽  
C. G. Windsor ◽  
N. Alford ◽  
D. D. Double
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Hardened Cement ◽  
Cement Pastes ◽  
Hardened Cement Pastes

Tricalcium Silicate (C3S) Properties in Different Physical and Chemical Environment

2013 ◽  
Vol 652-654 ◽  
pp. 1256-1259
Author(s):  
Lai Guo Wang ◽  
Wei Huang ◽  
Jun Wei Wang
Keyword(s):  
Neutron Scattering ◽  
Cement Paste ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Bound Water ◽  
Tricalcium Silicate ◽  
Chemical Environment ◽  
Paper Study ◽  
Scale Range ◽  
Physical And Chemical

The paper study on the properties of Tricalcium Silicate (C3S) in different physical and chemical environment, the results suggest that neither chemically nor by way of adsorption and that the physically bound water could not act as a solvent for the ethanolamine. Small-angle neutron scattering studies allow a nondestructive description of statistically representative microstructures in the scale range from micrometer to nanometer. Moreover, the scattering signals can be analyzed in a variety of ways, and more detailed insight can be provided into the very complex cement paste microstructure.

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